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Environmental variability within inbred lines and single crosses of maize


Within-plot coefficients of variability of F1 maize hybrids and of their inbred parents were determined for several plant and ear characteristics over a two-year period.

The heterozygous hybrids as a group were found to be better buffered (lower coefficients of variation) than the homozygous parents in every characteristic. There appeared to be significant differences in buffering among the hybrids only for ear node height; the inbred parents, however, differed significantly among themselves in buffering for plant height, ear node height, maturity, ear weight, and ear length.

These results suggest that any proposal designed to explain homeostasis in maize must satisfy these two kinds of evidence: heterozygote superiority and differences among homozygotes.

A proposal is outlined invoking systems of alternative biosynthetic pathways which function under different environmental optima. These systems are controlled in maize heterozygotes by alternative alleles of a single gene or by non-alleles of two or more loci. In maize homozygotes they are controlled by non-alleles. The essential role of genic function at diverse environmental optima is emphasized.

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Correspondence to D. B. Shank.

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Approved for publication by the director of the South Dakota Agricultural Experimental Station as Journal Series No. 417.

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Shank, D.B., Adams, M.W. Environmental variability within inbred lines and single crosses of maize. J Genet 57, 119–126 (1960).

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  • Plant Height
  • Inbred Line
  • Maize Hybrid
  • Pure Line
  • Single Cross